Compressor



Jan. 25, 1938.

J. C. MQCUNE COMPRESSOR Filed Feb. 24, 1934 4 Sheets-Sheet 1 Noi Jan. 25, 193s. Jg; MCCUNE. 2,106,488

COMPRESSOR.'

Filed Feb. 24, 1934 *4 sheets-sheet 2 IINVENTORV JOSEPH o. Mc @UNE A TTORNE Jam 25, 1193s. J C, MCCUNE 2,106,488

COMPRESSOR Fied Feb. 24, 1934 4 sheets-sheet s ATTORNEY Jan. 25, 1938.

J. C. MCCUNE COMPRES SOR Filed Feb. 24, 1954 8 4 SheelZs-Shee?I 4 IIE -3O IIIII INVENTOR JOSEPH C. Mc CUNE ATTORNEY Patented Jan. 2li, 1938 PATENT OFFICE COMPRESSOR Joseph C. McCune, Edgewood, Pa., assigner to The Westinghouse Air BrakeCompany, Wilmerding, Pa., a-corporation of Pennsylvania Appiiation February 24, 1934, serial No. 712,731

My invention relates to fluid compressors and particularly to electric motor driven compressors of the multi-cylinder type.

It is an object of my invention to provide a compact and relatively light weight multi-cylinder compressor.

Another' object is to provide a self-contained motor driven iluid compressor unit wherein a sectional casing constituting the housing for the compressor, the motor, and a fan may be readily formed and assembled into a compact unit occupying a minimum of space.

Another object of my invention is to provide an improved fluid compressor casing adapted to form a crank case chamber, a cooling chamber or passage,-a discharge chamber or passage, and an intake chamber or passage within the casing.

Another object is to provide a compressor. unit wherein iluid to be compressed may be supplied g() to the compressor cylinders under pressure from the cooling chamber oi the compressor or from anexternal source.

Another object is to provide a highly efficient uid compressor capable of operating at high 5 speeds which I, in part, accomplish by radially disposing thecompressor cylinders a'ndby providing uidinlets for the compressor cylinders, which inlets are controlled by the corresponding fluid compressing pistons inthe respective cyl- 3i, inders.

Another object is to provide an improved compressor unit having a casing for a radial cylinder type compressor, a fan, and a driving motor, in which the cooling air for the motor and the compressor enters one end of the casing axially,

passes the motor, and discharges past' the compressor cylinders through radial openings at the other end of the casing, which openings respec' pose of inspection, repair or replacement.

The above objects and other additional objects 1.1 of my invention that will be made apparent lubsewherein is employed an improved discharge valve device which may be assembled as a unit and removed from the compressor as a unit f'or the pur-Y (cl. 23o-211)" quently are attained by means of the compressor unit hereinafter described and illustrated in the accompanying drawings, wherein Fig. 1 is a longitudinal sectional view, partly in elevation, of a compressor unit embodying fea- 5 tures of the invention; Y

Fig. 2 is a transverse sectional view through the unit taken on the line 2--2 of Fig. 1;

Fig. 3 is a fragmental sectional view of a detail, taken on the line 3-3 of Fig. 2; 10

Fig. 4 is av transverse sectionalview ol' the unit taken on the line 4 4 of Fig.` 1, with a portion broken away;

Fig. 5 is atransverse sectional view of the unittaken on the line 5-5 of Fig. l; 415

Fig. 6 is a' transverse sectional view of the unit taken on the line 6-6 of Fig. 1;

Fig.`7 is a iragmental sectional view through a compressor cylinder, taken on the line 'l-'l of Fig. 1; 20

Fig. 8 is a top plan view of a fragment of the 1 unit showing a compressor cylinder and head;

Fig; 9 is a fragmental vertical sectional view of a cylinder and headshowing an improved form of discharge valve device; 25

Fig. .10 is an enlarged.isometric view .of the spring retainer of the discharge valve shown in Fig. 9;

Fig. 11 is a iragmental sectional View of the plunger pump of the lubricating system; and

Fig. 12 is a transverse sectional view of-'the plunger pump, taken on the line I2--I2 of Fig. 11

Referring to the drawings and particularly to Figs. 1 to 6, the compressor unit comprises acasing or housing made of metal section comprising a fan housing section I2 including a part of the motor housing or casing, motor casing sections I3 and I4 and a compressor casing section I5 which contains a suitable number of radially disbe hereinafter described, and a compressed air discharge chamber I9. The wally 2| has three radially disposed cylinder portions 23, as'shown in Figs. 1 and 5 in which the compression cylin- 50 lciers I6 are respectively mounted so that an annular inlet chamber 20 for the fair to be compressed is formed between each of the cylinders I6 and the wall portion 23. Furthermore, the cylinders are suitably adapted to be removable ,f

from the wall portions 23, as shown in Figs. 1 and 5, by being lifted radially outward, for purposes of repair or replacement.

The annular inlet chamber 2li surrounding each compression fcylinder I6 communicates with an arcuate inlet chamber 24, as shown in Figs. 1

and 4, through passages 215, the inlet chamber 24 y being formed in the casing section I4, ythe upper portion of the chamber being connected to an inlet pipe which is open to the atmosphere.

The wall 25 of the casing section I4 is provided the motor chamber II into the cooling air cham-` ber I8 is caused to flow past the cooling vanes 29 for the purpose of maintaining the cylinders and associated parts at the proper operating temperature.

The upper end of each of the compression cylinders I5 is closed bymeans of a head casing 32, as shown in Figs. 1, 5, and 9, which is suitably secured to the casing ,IW as by machine screws or bolts, and which serves to secure the cylinders I6 to the wall portions 23. Each of the `head casings 32 is provided with a discharge chamber 33 containing a discharge valve device to be hereinafter described, the discharge chamber 33 being connected to the discharge chamber I9 in the casing section I5 by means of passages 434 which register 'with openings 35 in the discharge chamber I9. The discharge chamber.

I9' is adapted to be connected to a receiver, not shown, by a discharge pipe 36, Figs. 5 and 6, one side of the discharge chamber being provided with 'a threaded opening 31 for receiving a discharge pipe in the event that it is desired to .con-

nect the discharge pipe tothe opposite side of the compressor. vAs indicated in Fig, 5 the threaded opening 31 is closed by means of a screw plug 35. l

The head casing 32 is provided with radial cooling ns 39 spaced apart so that air passages 40, Figs. I and, are provided between them through which air passing to the atmosphere from the radial passages 3|, flows, thereby carrying away the heat conducted tothe head from the associated parts of the mechanism.

Alfeature 'of the improved compressor appa-l ratus is the discharge valve device which, as will hereinafter appear, is a self-contained unit which may be assembled in the mechanism as a unit and withdrawn therefrom for the purpose of inspection and repair as a unit.

Referring to Figs. 9 and 10 the discharge valve device includes a valve seat disc 4I that is adapted to-be seated in an annular recess 42 in the outer face of the compression cylinder I6 and which is provided with a series of discharge ports 43 that are adapted to be closed by an annular 1 valve disc 44. Disc 44 is; mounted for sliding engagement upon a central stem 45 which is integral with the valve seat disc 4I and which is provided at its end with an enlarged head 45 for a purpose that will hereinafter appear. A tubular spring retainer 41 is provided, having a flange 45 that is adapted to be centered in a circular recess 45 in the head casing32 when the head is in assembled position upon the cylinder I5. The spring retainer 41 is provided at its other end with a portion 5I having an inwardly directed flange 52 that is provided with a slot 55 of such shape that it permits o! the assembly of the spring retainer upon the valve seat disc 4I by a lateral movement with respect to the disc, the head 45 of the stem 45 serving to limit the longitudinal displacement of the spring'retainer 41 with respect to the disc 4I when the head casing 32 is removed from the cylinder casing I5. A helicalk come the combined pressure of the uid within the discharge chamber 33` and that exerted by the spring 53 which opposes opening movement of the valve disc 44. l

From the foregoing, it is apparent that the discharge valve assembly consists .of the seat disc 4I, the valve disc 44, the spring retainer 41 and the spring 53, which elements are retained in assembled position by reason of the engagement of the enlarged head 45 with the flange 52 of the spring retainer. To assemble the discharge valve unit upon the cylinder casing I5, the valve disc seat 4I is rstplaced in the recess 42. A gasket 54 is then placed over the valve seat disc 4I and the head casing 32 is next placed over the spring retainer 41 so that the flange 45 enters the recess 49, as indicated in Fig. 9. when the head casing 32 is forced into engagement with the end of the wall of cylinder I 5 by means of the head bolts 55, the spring 53 is compressed and the parts occupy the position shown in Fig. 9. Opening travel of the valve disc 44 is limited by engagement of the disc with the flange v52 of the spring retainer 41.

When it is desired to inspect or repair the discharge valve, the head casing 32 is first removed after which the discharge -valve unit may be readily removed as a unit.

ThevcompressorY unit herein@ disclosed is of the multi-cylinder type comprising, for example,

three compression cylinders. each of which con-- tains a' piston 55 operated by the usual connecting rod 51 that is connected by meari's of anti-friction bearings 58 to a crank arm 55 carried on the end of a crank shaft 5I. The crank shaft is mounted for rotation in antifricticn bearings `52 and 53,

spectively, and is provided with a counter-weight 54 for counterbalancing the crank arm 55 and its associated moving parts. As will be clearly seen in Fig. 1, the motor armature 55 is secured to shaft 5I between the bearings 52 and 53, and the rotative impulse is thus applied to the shaft bythe motor.

The motor armature and ltsmassociated parts, as well as the compressor cylinders I5 are adapted to be cooled by air drawn into the casing sections through an end opening 55 in the casing section I2. A protection screen 51 is provided to cover the opening 55 and a conicai inlet collar 55 which is secured to the casing section I2 with the screen, serves to direct air into the central portion of a `centrifugal fan 55.

The ian 55 is of the centrifugal blower type, in

' secured'within the casing sections I4 and' l12, reu I which a series of spaced arcuate vanes 1| are arranged about the periphery of the disc-like body 12 as indicated in Figs. 1 and 2 so that when the fan is rotated by the motor in a clockwise direction in Fig. 2, the air drawn through the screen 61 and inlet collar 68 leading to the central portion of the fan is discharged radiallyand in the direction of rotation of the ian so that the air discharged from the fan is given a gyratory motion within the`fan chamber 13. The Wall of the fan chamber casing section |2 is formed in the shape of a spiral, with an inner extension 14 thereof terminating at a point 15 adjacent the periphery of the fan, so that a discharge channel 16 i's defined by the extension 14, which channel expands spirally in cross-sectional area to a point opposite the point 15 at the extremity of the extension 14. From a point opposite the point 15, the channel defined by the outer face of the extension 14 and the outer wallof the casing section I2, diminishes in cross-sectional area until it reaches an opening 11.-

A hinged cap or cover 18 is yieldingly held in a position to close the opening 'l1 by4 a spring 19 under the control of a latch member 8| which is pivot-ally connected to the casing i2 and which engages the spring 19 so that when the latch member 8| is in the position shown, the spring is retained in closure closing position. The partition wall 82 of the casing section I2,

which constitutes one of the walls of the channel 16, is provided with an opening 83 in a part thereof between the wall 14 and the outer wall of the casing section l2, through which opening the air discharged from the fan within the fan chamber may flow tothe motor chamber A screen 84 that is removably connected to the casing section l2 by means of the screws 85,- is provided for covering opening 83. The lower extremity of the passage 16 adjacent the opening 11 constitutes a trap for receiving foreign p articles carried into the fan chamber in suspension in the air, the wall 14 being provided with a downwardly depending web 88 for preventing f such a back flow of air from the trap as would carry the foreign particles out ofA the trap. Accumulations of foreign particles within the trap may be removed through the opening 11 4by manually opening the cover 18 against the action of the spring 19.

A further feature of the improved compressor mechanism is an vimproved pump for circulating fluid lubricant so that the lubricant is forced through a passage 81 into the crank arm 59 from which it ows to the bearings 58 for the connecting rods through passages 88. Referring to Figs. 1, 11 and 12, the pump mechanism comprises a member forming a compression chamber 89, removably secured to casing section i5, and a pump piston 9| which is adapted to reciprocate within the chamber 89. The piston 9| is provided with a valve chamber 92 that is open to the crank chamber |1 through an opening 93 through which fluidl lubricant in the crank chamber |1- may flow into the valve chamber 92 of the piston 9|. The piston is' provided at its lower end with a port or opening 94 through which fluid flows from the chamber 92 into the compression chamber 89. A reciprocating plunger 95 for moving piston 9| is provided with an enlarged head 9S which is adapted to reciprocate through a short distance within the chamber 92, as will be hercinafter further explained, the plunger also having a longitudinal passage 91 extending therethrough in which a ball check valve member 98 is disposed for closing a port 99 in the lower end ,of the plunger. A pin |00 is provided which extends transversely through the plunger a short distance from the valve member 98 for vthe purpose of limiting the extent of movement thereof with respect to port 99.

The plunger 95 is journaled at its upper end upon a crank pin |0|, Fig. 1, that is carried upon ihe crank arm 59 and which is'eccentric to the axis of rotation of the crank shaft 6| so that as the crank shaft 8| is rotated, the plunger 95 is reciprocated. The.l passage 91 in the plunger is connected to the passage 81 in the crank arm 59 and crank pin |0|, so that fluid lubricant which is forced into the passage 91 in the plunger, flows -to the bearings through the passages 81 and 88, the lubricant passing the bearings and the choke passage |02 in the crank arm 59 after which it flows into the crank chamber |1 from whence it may reurn to the chamber. 92 in the piston 9|.

The lower end of the plunger, that is, the enlarged head thereof, is provided with a substantially spherical surface |03l which is adapted to engage the inner conical end surface |04 of the piston 9| so as to make sealing engagement therewith on the downstroke of the plunger and maintain such sealing engagement regardless of angular movement of the plunger 95 with respect lo the piston 9|. The enlarged head 96 is loosely connected to the piston 9| by means of a bushing |08 having a conical end surface |09 flaring downwardly toward thehead 96, the bushing being supported on an interorly extending shoulder ||0 in the wall of pison 9|, and secured thereon by bending orfpeening over the end of the piston wall.

When the plunger 95 is raised from the position shown in Fig. 11, it moves a short distance before the enlarged head 96 strikes the conical surface |09 of the bushing |08, and thereby is effected the lost motion or loose connection between the plunger 95 and the piston 9|, above referred to.`

Upon the upward stroke of the piston plunger 95, the spherical 4surface of the enlarged head96 is separated from the conical surface |04 of thc piston 9| so that as the piszonl 9| is moved upwardly by the plunger, oil or lubricant uid may flow through the opening 93 in the piston past the enlarged head 96 of the plunger` and through the port 94 into the compression chamber 89, the ball check` valve member 98 at such time remaining seated so that it closes the port 99 in the lower end of the plunger. Upon the downward stroke of the plunger, the spherical surface |03 initially moves into sealing engagement with the conical surface |04 of the piston, thereby preventing any passage of fluid lubricant from the compression chamber -89 into the chamber 92 in the piston and transmitting a downward force to move the piston 9| downwardly. As the piston is movedY downwardly by the plunger 95, it exerts a compressive force on thefiuid lubricant within the chamber 89 and causes the fluid to pass through thel ports 94 and 99', past the check valve ball member 9 8 into the passage 91, and thence to the bearings through the passage 81. Upon the subsequent upward stroke of the plunger 95, the ball member 98 seats and thereby closes thc port 99, thus preventing the fluid in the passage `91 from fic-wing therefrom back into chamber 89 through the passage 99. As previously stated, during the upward stroke of the plunger 95, the spherical surface of the head 96 separates from the conical surface-|04 of the piston, and fiud lubricant flows into the chamber 92 of the piston due to the gravitational force or pressure head of the fluid lubricant within the crank case, thence through the port 94 in the lower end of the piston into the chamber 89 from whence it is discharged into the 'passage 91 in the plunger upon the subsequent downward stroke of the plunger.

By reason of the pump construction just described, wherein a free passage is provided for the flow of iluid into the compression chamber under a gravitational head, the compression chamber 89 is completely lled during every cycle of operation of the pump, regardless of the speed of operation of the plunger. Consequently regardless of the speedof operation of the compressor, the bearings for the connecting rods are lubricated properly, thus prolonging the life of the compressor. i L

In the operation of the compressor, the rotation of the fan 69 within the fan chamber 13 causes air to be drawn into the fan chamber in the manner describedand forced through the screened opening 83 in the partition wall'82 into the motor chamber containing the motor armature 6,5. The large volume of air forced past the motor armature and its associated stator winding maintains the motor at the proper operating temperature. Subsequently the air passes from the motor chamber into the cooling chamber I8 through the openings |05 in the end wall 26 of the casing section |4, around the cylinders` I6, and is discharged to the atmosphere through the respective radial passages 3|, past the iins 29 and 39 on the cylinders I6 and the head casings 32, thus carrying away the heat generated during the compressing operation of the compressor.

. Air for compression is drawn into inlet chamber 24 of the compressor unit through the inlet pipe 30 which is connected thereto, and thence it passes to the inlet chamber surrounding each of the`piston cylinders i6 through corresponding passages 25, the air entering the compression chambers |06 above the various pistons 56 through a plurality of peripheral ports' |01 in the wall of each cylinder I6 when the corresponding piston is at the bottom of its stroke.

l Upon the upward stroke of each of the pistons, the ports |01 are rst closed and then the trapped air is forced past the discharge valve device, Ypreviously described, into the associated discharge chamber 33, and is dischargedy to the receiver pipe 36 through passage 34 and discharge chamber I9.

In the event that it is desired to force air into the compression chambers under pressure, the inlet pipe 30 is closed in vany suitable manner and the plugs 28 are removed from their respective threaded openings 2T, thereby permitting air under pressure to ilow 'from the motor chamber |I into the inlet chambery 24 through the threaded openings 21 and from thence through the ports |01 in the cylinders I6 to the compression chamber above the piston. The manner of supplying air to the compression chambers of the compressor is therefore, optional.

vIt will,',therefore, be seen that an improved, compact and 4self-contained fluid compressor unit has been disclosed wherein is provided an improved sectional casing which serves in directing the iiow of cooling air for the compressor and its driving motor in a novel manner, which is adapted to form a crank case chamber, a cooling chamber and a compressed fluid discharge chamber for the compressor in a simple compact arrangement. land which is adapted to permit fluid under pressure from the cooling chamber of the compressor to be supplied to the compression cylinders of the compressor, while also providing optionally for the supply of uid at atmospheric or other pressure to the compression cylinders from an external source.

It will also be seen that there has been disclosed an improved compressor of the radial cylinder type in which the fluid inlets for the respective compressor cylinders are controlled by the compressor pistons operating in the cylinders.

It will also be seen, furthermore, that there has been disclosed a compressor wherein is provided an improved plunger pump for circulating uid lubricant for the moving parts of the compressor, and wherein is provided an improved discharge valve device capable of assembly and disassembly as a unit.

It will be seen, lastly, that there has been disclosed a compressor unit provided withan improved means for cleaning the cooling fluid therefor.

While but one embodiment of my invention is herein disclosed, it is obvious that omissions. additions, and other changes may be made in the construction without departing from the spirit of the invention. l

Having now described my invention, what I vclaim as new and desire to secure by Letters Patent, is:

1. A iluid compressor comprising a casing, a cylinder mounted in said casing, a piston operable in said cylinder, a fluid inlet port in said cylinder, controlled by the movement of said said cylinders operable respectively therein, a

fluid inlet passage for each'of said cylinders controlled by the movement of the piston in the corresponding cylinder, means providing a passage connecting said inlet passages and having a connection to the'atmosphere, means providing a cooling chamber for said cylinders and having a connection between said cooling-chamber and said connecting passage whereby fluid supplied to said cooling chamber may also be supplied to said connecting passage, and means for closing said last connection.

3. A iluid compressor comprising a casing, a plurality of radially disposed cylinders mounted in said casing, a uid compressing piston in each cylinder, a crank shaft operatively connected to said pistons for operating the said pistons in their respective cylinders, and a motor for driving said crank shaft, said casing having an outer arcuate wall,an inner arcuate wall forming a crank case chamber for said crank shaft, and an intermediate arcuate wall forming at one side thereof. a cooling chamber for said cylindersand at the opposite side thereof a fluid discharge chamber for said cylinders.

JOSEPH C. MCCUNE. 

